Connectionists: NEW PAPER: Scale Free Exponents of Resting State...

[Stephen José Hanson]

Please find a new paper on Resting state dynamics as estimated from
fMRI.

We show in large samples (100s of subjects) that estimated scale-free
exponents
are significantly larger (30%+) in both atyptical brain activity
(autistic spectrum disorder and schziophrenia) and in a known regime
that is associated network breakdown of communication and fractioned hub
structure.    A known phase transition in scale-free structure predicts
this breakdown.

This is not due to correlation measures as we use graphical estimation
and conditional independence.
We estimate graphs using an extended Power+ set (283 ROIs)--39k edges.

This is not due to motion differences as we demonstrate using
overlapping motion frame displacement
measures and recompute exponents showing *no change* in value as motion
varies from sub-samples
of subjects with similar or disparent motion range.

This is shown not to be due to the type of estimator (MLE, LSE, MOM,
etc) which all agree
in the phase transition exponent change point (1.8).

We show phenotypic disease severity correlates with exponent increases.

We provide confirmatory SVM classifier results on the EDGES of estimated
graphs
showing with 10-fold cross validation that we can discriminate between
Neurotypical
(120 independent observations) to the Atypical (120 ASD, SZH independent
observations) .

Any queries or comment-->  SJH.

Thanks for your interest in this work.

https://arxiv.org/abs/1605.09282

Cheers,

Steve Hanson



-- 
Stephen José Hanson
Director RUBIC (Rutgers Brain Imaging Center)
Professor of Psychology
Member of Cognitive Science Center (NB)
Member EE Graduate Program (NB)
Member CS Graduate Program (NB)
Rutgers University 


email: jose at rubic.rutgers.edu
web: psychology.rutgers.edu/~jose
lab: www.rumba.rutgers.edu
fax: 866-434-7959
voice: 973-353-3313 (RUBIC)



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